| Class | A template, or a blueprint, from which Java objects are created. All Java programs start with a class. |
| Object | An object is a single instance of a Java class. An object has both state and behavior. |
| Object Oriented Programming | Programming model that focuses on objects and the data and actions associated with the objects. |
| State | The state of an object is all of the object’s associated data. It is the state that the object is in. |
| Behavior | The behavior of an object is what the object is able to do. It is the actions that can be performed by the object. |
| Instance | Instance is what you call a specific object constructed from a class. Instance and object generally refer to the same thing. An object is a specific instance of a class. |
| Method | A method is a way to teach the computer a new command |
| String | String is a Java type that represents a string of characters (text) |
| Instance Variable | A variable defined in a Class, for which each object of the class has its own copy. |
| Constructor | A constructor is a special method of a Class that constructs a new object (a new instance) of the Class and sets the initial values for the instance variables. |
| toString | toString is a special method you write in your class that returns a String representation of the object. |
| Parameter | A variable passed into a method from outside the method. |
| Return type | A method’s return type is the type of value returned from that method. |
| Method signature | A method’s method signature is the name of the method and the parameter list. |
| Instance Method | An instance method is a method that defines the behavior of an object. It defines an action that the object can perform. |
| Visibility | Visibility (usually public or private) defines who has access to something (usually a variable or method). Public means code outside of the class can access, private means only code inside the class can access. |
| Static method | A method called on the Class, rather than on a specific object of the Class. |
| Package | Related classes are grouped together into packages. |
| this | The this keyword is a reference to the current object (the current instance). |